The work arounds have no affect. Cause the BIOS is the thing that can reassign the drive letters and drive ID which can mess up the boot. So no matter what "work arounds" you may have installed. 1 time removing that drive from the system and putting it back on can easily destroy your boot and cause your system to not work. It is the UID or Universal ID that the BIOS assigns to the drive that matters, not what drive letter is assigned within Windows. The UID will be replaced if that drive is ever disconnected from the unit and cause your boot not to work.
So i certainly hope that you dont have a system failure or time where the drive gets disconnected while the unit is in operation. Cause that will most certainly cause you issues. Especially since Win7 is not made to install to an External device at all. No matter what the drive letter is, which means that it was more than a "cheeky work around". It was straight up hacking the OS to do something it was not created to do.